Winding mechanism of blind

ABSTRACT

A winding mechanism mounts at a groove of a head rail of a blind and comprises a cord wrapped around a bottom stiffener strip and the head rail, a rope roller, a rope wound around the rope roller and coupled to the cord, a first roller coupled to the rope roller by gear, a second roller, and an S-shaped spring interconnected the first and second rollers, the spring adapted to exert a force to support the drapery material. In a downward pulling of the stiffener strip the rope roller rotates to release the rope and the cord with one worm section of the spring being further wound and the other worm section thereof being loosened for reaching a balance with the blind. An upward pulling of the same has an opposite effect. The drapery material is able to stay at any position in response to stopping the rope roller.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to blinds and more particularly to a winding mechanism of a blind (e.g., roll-up or Venetian blind) with improved characteristics.

2. Related Art

Typically, a blind (e.g., roll-up or Venetian blind) is adapted to raise or lower by pulling a lift cord coupled to a winding mechanism. However, it is possible that a child may tie the exposed cord about the neck to cause danger or even death. Thus, this is not safe.

A conventional roll-up blind having a hidden lift cord is shown in FIG. 1 and comprises a head rail 1 fixed to a top of window frame, two spaced, opposite springs 2 in the head rail 1, a bottom stiffener strip 3, a plurality of folds 4 coupled between the head rail 1 and the stiffener strip 3, each fold 4 having two openings proximate both sides, two side rails 5 and 6 of U-section fixed at both sides of the window frame, the side rails 5 and 6 adapted to allow both ends of the folds 4 to longitudinally slide therein, and two cords 7 and 8 in which the cord 7 has one end passed the left openings to couple to one spring 2 and the other end tied off at the left side rail 5, and the cord 8 has one end passed the right openings to couple to the other spring 2 and the other end tied off at the right side rail 6.

However, the previous design suffered from several disadvantages. For example, the springs 2 tend to lose its elasticity after a predetermined times of lowering or raising operation of the folds 4. And in turn, it may compromise the positioning capability of folds 4 by operating the cords 7 and 8. Further, there are no guide members for the cords 7 and 8 in the head rail 1 and the stiffener strip 3. It may increase friction in pulling the cords 7 and 8 during operation. To the worse, the cords 7 and 8 may break after a predetermined times of lowering or raising operation. Furthermore, the stiffener strip 3 is relatively thin, resulting in a poor maneuverability of the blind.

Thus, it is desirable to provide an improved winding mechanism of blind in order to overcome the above drawbacks of prior art.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a winding mechanism mountable at a groove of a head rail of a blind, the blind further including a bottom stiffener strip and a sheet of drapery material coupled between the head rail and the stiffener strip, comprising a cord having one end tied off at a first position of the stiffener strip, passed one side of the sheet of drapery material, the head rail, and the other side of the sheet of drapery material, and having the other end tied off at a second position of the stiffener strip; a rope roller; a rope wound around the rope roller and coupled to the cord; a first roller rotated with the rope roller by gear meshing; a second roller; and a spring interconnected the first roller and the second roller, the spring including two worm sections together formed an S, the spring adapted to exert a force to support the weight of the sheet of drapery material, wherein in a downward pulling of the stiffener strip the rope roller rotates to release the rope and the cord for lowering the sheet of drapery material with one worm section being further wound and the other worm section being loosened as a counterweight of the sheet of drapery material so as to reach a balance, thereby maintaining the sheet of drapery material at any one of a plurality of positions from a fully raised position to a fully lowered position in response to stopping the rope roller, and in an upward pulling of the stiffener strip the rope roller rotates in an opposite direction to wind the rope and the cord for lifting the sheet of drapery material with one worm section being loosened and the other worm section being further wound as a counterweight of the sheet of drapery material so as to reach a balance, thereby maintaining the sheet of drapery material at any one of a plurality of positions from the fully raised position to the fully lowered position in response to stopping the rope roller.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a conventional roll-up blind;

FIG. 2 is an exploded view of a first preferred embodiment of winding mechanism to be mounted on a roll-up blind according to the invention;

FIG. 3 is a perspective view of the assembled winding mechanism and blind of FIG. 2;

FIG. 4 is a top view in part section of the winding mechanism;

FIG. 5 is a greatly enlarged, exploded view of the winding mechanism;

FIGS. 6 and 7 are transverse and longitudinal sectional views of the winding mechanism respectively;

FIG. 8 is a perspective view of the raised blind of the invention; and

FIGS. 9 and 10 are transverse and longitudinal sectional views of a second preferred embodiment of winding mechanism of blind according to the invention respectively.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2, 3 and 4, there is shown a winding mechanism 40 in accordance with a first preferred embodiment of the invention. The winding mechanism 40 is to be mounted on a roll-up blind 30 comprising a head rail 10 of U-section, a bottom stiffener strip 20, and a sheet of drapery material 30 coupled between the head rail 10 and the stiffener strip 20 and comprised of a plurality of folds 31 each having two openings 32 proximate both sides. A plurality of spaced guide rollers 11, 12, 14, and 15 and the winding mechanism 40 are disposed in a groove 11 of the head rail 10. The guide rollers 11, 12, 14, and 15 are coupled together by a continuous cord 13 wound around them. Two ends of the cord 13 pass two bottom apertures (not shown) and the openings 32 to tie off in the stiffener strip 20. The guide rollers 11, 12, 14, and 15 are adapted to guide the cord 13 in its pulling operation (i.e., more smooth). Note that the sheet of drapery material 30 and its folds 31 of the roll-up blind in this embodiment can be replaced by slats of a Venetian blind in the other embodiment.

Referring to FIGS. 5 to 7, the winding mechanism 40 comprises a case 41 open to its bottom, the case 41 having an internal space 42 for mounting a rope roller 43, a first roller 44, and a second roller 45 therein. Three shafts 46 each has two ends fixed on two opposite walls of the case 41 with the rope roller 43, the first roller 44, or the second roller 45 rotatably put thereon. A spring 47 is interconnected the first roller 44 and the second roller 45. The spring 47 comprises two worm sections 471 and 472 together formed an S. The spring 47 can exert a force to support the weight of the sheet of drapery material 30. A free end 48 of the worm section 472 is fixed on the first roller 44. A long rope 49 is wound around the rope roller 43 and the guide rollers 11, 12, 14, and 15 and its winding is opposite to that of each of the worm sections 471 and 472. One end of the rope 49 passes one of two slits 411 on one side surface of the case 41 to couple to the cord 13. As such, the rope 49 and the cord 13 can operate as a whole. The rope roller 43 comprises a gear 412 at one end to be meshed with a gear 413 of the first roller 44 such that the rope roller 43 and the first roller 44 can rotate in opposite directions.

The S-shaped spring 47 is energized due to the same winding direction of the worm sections 471 and 472 and the weight of the sheet of drapery material 30. A downward pulling of the stiffener strip 20 by the hand together with the weight of the sheet of drapery material 30 can overcome an upward pulling force of the cord 13 provided by the spring 47. As such, the rope roller 43 rotates to release the rope 49 and thus the cord 13 so as to lower the sheet of drapery material 30. The worm section 471 is wound further (i.e., store energy) and the worm section 472 is loosened to compensate the further winding of the worm section 471 during the release. Such serves as a counterweight of the sheet of drapery material 30 so as to reach a balance. As a result, the sheet of drapery material 30 is adapted to stay at any one of a plurality of positions from the fully raised position to the fully lowered position by stopping the rope roller 43.

Referring to FIG. 8, an upward pulling of the stiffener strip 20 by the hand together with the compression force of the spring 47 can overcome the weight of the sheet of drapery material 30. For reaching a balance, the worm section 471 coupled to the first roller 44 begins to release and the worm section 472 coupled to the second roller 45 begins to wind. A force exerted onto the rope roller 43 by the spring 47 is thus adjusted. Also, a rotation of the first roller 44 will cause the rope roller 43 to rotate the same for winding the rope 49. Likewise, the sheet of drapery material 30 is adapted to stay at any one of a plurality of positions from the fully raised position to the fully lowered position by stopping the rope roller 43.

Referring to FIGS. 2 and 3 again, the winding mechanism 40 further comprises a retaining member 50 including an elongate seat 51 engaged with a bottom surface of the stiffener strip 20 and two upwardly curved snapping edges 52 along front end rear edges of the seat 51 for clamping the stiffener strip 20. The provision of the retaining member 50 aims at facilitating the upward or downward pulling the stiffener strip 20 by the hand.

Referring to FIGS. 9 and 10, a second preferred embodiment of winding mechanism 60 of blind according to the invention is shown. The winding mechanism 60 comprises a case 61 open to its bottom, the case 61 having an internal space 62 for mounting a third roller 63 and a fourth roller 64 therein. Two shafts 65 each has two ends fixed on two opposite walls of the case 61 with the third roller 63 and the fourth roller 64 rotatably put thereon. An S-shaped spring 66 is interconnected the third roller 63 and the fourth roller 64. A free end of the worm section 66 is fixed on the third roller 63. A rope roller 67 is coaxially formed at one side of the third roller 63. A long rope 68 is wound around the rope roller 67. One end of the rope 68 passes a slit on one side surface of the case 61 to couple to a cord 70. As such, the rope 68 and the cord 70 can operate as a whole.

In practice, each of the springs 47 and 66 can control one or more rope rollers 43 for accommodating different sizes of the blind. In brief, the invention is safe and smooth in its operation.

While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. 

1. A winding mechanism mountable at a groove of a head rail of a blind, the blind further including a bottom stiffener strip and a sheet of drapery material coupled between the head rail and the stiffener strip, comprising: a cord having one end tied off at a first position of the stiffener strip, passed one side of the sheet of drapery material, the head rail, and the other side of the sheet of drapery material, and having the other end tied off at a second position of the stiffener strip; a rope roller; a rope wound around the rope roller and coupled to the cord; a first roller rotated with the rope roller; a second roller; and a spring interconnected the first roller and the second roller, the spring including two worm sections together formed an S, the spring adapted to exert a force to support the weight of the sheet of drapery material, wherein in a downward pulling of the stiffener strip the rope roller rotates to release the rope and the cord for lowering the sheet of drapery material with one worm section being further wound and the other worm section being loosened as a counterweight of the sheet of drapery material so as to reach a balance, thereby maintaining the sheet of drapery material at any one of a plurality of positions from a fully raised position to a fully lowered position in response to stopping the rope roller, and in an upward pulling of the stiffener strip the rope roller rotates in an opposite direction to wind the rope and the cord for lifting the sheet of drapery material with one worm section being loosened and the other worm section being further wound as a counterweight of the sheet of drapery material so as to reach a balance, thereby maintaining the sheet of drapery material at any one of a plurality of positions from the fully raised position to the fully lowered position in response to stopping the rope roller.
 2. The winding mechanism of claim 1, wherein the winding mechanism further comprises a retaining member including an elongate seat engaged with a bottom surface of the stiffener strip, and two upwardly curved snapping edges along front end rear edges of the seat for clamping the stiffener strip.
 3. The winding mechanism of claim 1, wherein the rope roller comprises a first gear and the first roller comprises a second gear meshed with the first gear such that the rope roller and the first roller are adapted to rotate in opposite directions.
 4. The winding mechanism of claim 1, further comprising a plurality of second rope rollers coupled to the spring.
 5. The winding mechanism of claim 1, further comprising a plurality of spaced guide rollers disposed in the groove and two holes formed on a bottom of the groove, and wherein the guide rollers are coupled together by winding the cord therearound, and two ends of the cord are adapted to pass the holes.
 6. The winding mechanism of claim 1, wherein the rope is wound in a direction opposite to that of each of the worm sections.
 7. The winding mechanism of claim 1, comprising a case for receiving the rope roller, the first roller, and the second roller therein. 